AGGRAVATION OF GINGIVAL INFLAMMATORY SYMPTOMS DURING PREGNANCY-ASSOCIATED WITH THE CONCENTRATION OF PLASMINOGEN-ACTIVATOR INHIBITOR TYPE-2 (PAI-2) IN GINGIVAL FLUID

Gingival inflammatory symptoms are aggravated during pregnancy. In vit ro studies suggest a hormonal influence on the plasminogen activator i nhibitor type 2 (PAI-2), and a disturbed balance of the fibrinolytic s ystem could help to explain pregnancy gingivitis. Gingival crevicular fluid (GCF) was sampled in 14 women in pregnant and post-pregnant stat es. The gingival condition was assessed by the gingival index of Lee & Silness (GI) and the amount of bacterial plaque by the plaque index o f Silness & Loe (PI): The ratio of sites with gingivitis to sites with bacterial plaque was calculated (G/P-ratio). Antigen levels of tissue plasminogen activator (t-PA), urokinase-type plasminogen activator (u -PA), plasminogen activator inhibitors type 1 (PAI-1) and PAI-2 in GCF were determined with ELISAs and 17 beta-oestradiol and progesterone i n serum with radioimmunoassays, For each individual the differences (D elta) in hormone levels and PAs and PAIs between pregnancy and post-pr egnancy were calculated. Based on differences in G/P-ratio between pre gnancy and post-pregnancy, subgrouping was done into a high-reacting a nd a low-reacting group. For the total group, the mean G/P-ratio was 2 .0 during and 1.2 after pregnancy (p=0.064). A statistically significa nt correlation between Delta progesterone and Delta PAI-2 was noted: t he higher Delta progesterone, the lower Delta PAI-2. No other signific ant correlations between hormone levels and components of the fibrinol ytic system were found. For the total group of women, the concentratio ns of PAI-2, PAI-1 and t-PA were significantly higher during than afte r pregnancy. The individuals in the high-reacting group, however, show ed a lower or unchanged production of PAI-2 during pregnancy, while th ose in the low-reacting group showed a greatly increased production. T he lower inhibitory capacity in terms of a low production of PAI-2 dur ing pregnancy in women with a higher inflammatory reaction indicates t hat the components of the fibrinolytic system may be involved in the d evelopment of pregnancy gingivitis and implies that PAI-2 serves as an inhibitor of importance for tissue proteolysis, The present finding c ontributes to the explanation of pregnancy gingivitis.